I decided to put a custom LED bulb set (15 3mm blue) and an incandescant in my map lights to get the white light with a tint of blue. It burned up the white incandescant light. Not just burned out, but actually MELTED the fuxor. The inside of my map light console required some repair to get it to work again after being melted. The bulb actually came out in 2 pieces, glass and metal separated.

Bottom line, incandescant and LED do not mix in the map lights.

 

bet it was very bright too. Chances are, those stock bulbs are actually 6v and the two are in series to make it a 12v system. LEDs do not take that much voltage.. you were probably running 10v though the lamp

 

oddly enough it seemed pretty darn dim. I'll look at the wiring diagrams later.